Improvement in grinding-machines



Y ZSheets-Shet 1'. B. G. LUTHER.- GRINDING MACHINE.

No.179'417. Patented July 4,1875..

N-FETERS, PHOTO-LITHOGRAFHER, WASHINGTON. D. CA

2 Sheets-Sheet 2.' B. G. LUTHER. GMNDING MACHINE; No.179,4.17 Patented July 4,1876.

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BENJAMIN Gr. LUTHER, OF PROVIDENCE, ASSIGNOR TO THE AMERICAN TVVIST-DRILL COMPANY, OF WOONSOCKET, RHODE ISLAND.

IMPROVEMENT IN GRINDING-MACHINES.

Specification forming part of Letters Patent No. 179,4l7, dated July 4, 1876; application led May 25, 187 6.

To all whom it may concern:

Be it known that I, BENJAMIN G. LUTHER, of the city and county of Providence, in the State of Rhode Island, have invented certain new and useful Improvements in Grinding- Machines; and I do hereby declare that the following specification, taken in connection with the drawings furnished and forming a part of the same, is a clear, true, and complete description of my invention, and o f a machine embodying the several features thereof.

My improvements relate to that class of machilies which are designed for dressing castings, and for general grinding service.

The main feature of my invention consists in a grinding-wheel and spindle mounted in a frame, which is pivoted at its upper end, and arranged at its lower end to be adjusted laterally, whereby the spindle may be set at any desired degree of inclination.

In connection with this feature my invention further consists in the combination, with a pivoted frame, which supports the grindingwheel spindle, of an adjusting-screw, whereby the frame and spindle may be readily inclined and held in any desired position; and also in the combination, with a sliding box-frame and an angularly-adjustable frame, of a treadleshaft, connected with the box-frame by a centrally-pivoted lifting-rod, whereby the boxframe, with grinding-wheel and spindle, may be readily raised or lowered, regardless of the angular position of the adjustable frame.

Another feature of my invention consists in the combination, with the grinding-wheel spindle and a vertically-sliding frame, which contains the journal-boxes of the grinding-wheel shaft, of a lifting-lever with suitable connections, a ratchet-bar, a pawl, and a pawl-controlling device, whereby the grinding-wheel spindle may be readily-raised or lowered and maintained at any required elevation.

Referring to the drawings, Figure l represents, in perspective, one of my grinding-machines. Fig. 2 represents the same in lateral vertical central section. Fig. 3 represents the same in longitudinal vertical central section. Fig. 4 represents, in perspective, the grindingwheel, its spindle and frames detached. Fig.

5 represents the bearings on which the spindle and its frame are mounted.

A denotes the frame of the machine. It is in the form of a table, with four legs and suitable braces. The top a of the table is the surface which supports the casting or other article to be operated upon by the grinding-wheel B. The wheel B, whether of emery or stone, is mounted upon the upper end of its spindle b, in a manner Well known. The spindle has an upper journal-box at c, and a lower box at d, and a belt-pulley at c, between the boxes. The' boxes c and d are formed in a box-frame, f, which has V-shaped edges, as is usual with slides. The box-frame is mounted in the adjusting-frame C, which has at each side a vertical groove for receiving the V-shaped edges of the box-frame. The adjusting-frame C has at its upper end two convex bearings, g, (one on each side,) which project in opposite directions from a hollow circular neck, which unites' the two sides of the frame. Each convex bearing has a concave box at h, which is secured to the under side of the table. The bearings g have a metallic strap, t, which, by extending from each end downward and beneath the concave box h,serves to maintain the two in proper position, While permitting the bearings g to move -in the boxes after the manner of a rock-shaft. The bearings g are rectangular to the main body ofthe adjustingframe, so that the lower end of the latter may be moved laterally in either direction. The lower end of the adjusting-frame may or may not be provided with a guide, although one is generally desirable. The segmental cross-bar at t extends from one side of the frame to the other, and if a guide be attached to the frame it can embrace the upper edge of said crossbar, and so prevent any possible movement of the lower end ofthe frame, except that movement which is necessary for attaining the desired angle of the grinding-wheel spindle. For adjusting the angle of the spindle and grinding-wheel I employ the lateral adjusting'- screw D, which is beneath the top of the ta.- ble, and extends from side to side of the machine, and is provided with a hand-crank at each end. This screw and the adjusting-frame are united by means of a sleeve-nut, k, swiveled to a link, Z, which is pivoted to the frame. An operative from either side of the machine may, by use of the adjacent crank, effect the desired angular adjustment ot' the spindle and grinding-wheel.

For vertical adjustment of the grindingwheel I employ the treadles E, ot' which there are two-one at each end of the treadle-shaft m, which has an arm or level', n, at the outer end of which a lifting-rod, o, is pivoted. The lii'tingrod o, at its upper end, is centrally pivoted to the boX-framef.

I am aware that grinding-wheel spindles have heretofore been mounted on a slide, and controlled by a system of levers, so that while the wheel is rotating it can be moved up and down, for presenting the entire face of the grinding-wheel for service 'during the grinding operation. I know of none, however, prior to my present invention, in which the spindle and wheel could be raised or lowered and ad justed for service at any desired elevation. My means of adjustment consist of a vertical ratchet-bar, p, mounted. on the rear of the treadle-lever u, and a spring-pawl, q, mounted upon the segmental cross-bar t", is arranged to engage with the ratchet-bar, except when the pawl is controlled by means ot thecrank-shaft r, which is mounted at the under side of the table, is provided with a crank at each end, and is connected, by means of a lever and a slender wire rod, s, with the pawl q.

The grinding-wheel is drivenv by a twisted belt, which may be employed in connection with the belt-tightener t.

In operation it will be seen that the edge face of the grinding-wheel ina-y be adjusted to any desired angle with relation to the supporting-surface of the table, and also that the wheel may be raised or lowered and readily adjusted at any desired elevation. The lifting-rod o, being pivoted centrally in the boxi'rame, enables it to operate readily in elevating the grinding-wheel, regardless of the angle at which its shaft may at the time be adjusted. rIhe circular opening in the top ofthe table, within which the wheel revolves, is beveled on two sides, to accommodate the wheel in its various positions. The adjustable frame has at its lower end a range ot' lateral movement, which enables the grinding-wheel shaft to be well inclined, as indicated in dotted lines in one of the sectional figures. The adjustment of the wheel is readily accomplished by the operative, at whichever side of the machine he may be at work.

I am aware that verticallyreciprocating grinding-wheels and spindles are not new, and that with such wheels tables have been employed which have tops adjustable at any desired angle. I am not aware, however, that prior to my invention such wheels have been mounted on angularly-adjustable spindles, or that such have been so mounted that they could be set and operated at various elevations.

Having thus described my invention, I claim as new and desire to secure by these Letters Patentl. rIhe combination, with a work-supporting table, oi' a grinding-wheel mounted on a spindle, which is journaled in a pivoted and laterally-adjustable frame,V substantially as described, whereby the grindingwheel may be operated with its working-face at any desired angle with relation to the work-supporting surface ofthe table, as set forth.

2. The combination, with the grinding-wheel and its spindle, of a pivoted frame and an adjusting-screw, substantially as described, whereby the wheel may be readily adjusted -at any desired angle, as set forth.

3. The combination, with a grinding-wheel, its spindle, and a journal-box frame mounted in slide-bearings, of a treadle-lifting rod, ratchetbar, and pawl, substantially as described, whereby the grinding-wheel may be raised or lowered and maintained at any desired elevation', as set forth.

4:. The combination, with a grinding-,wheel and spindle, mounted in a slidingjournal-box frame, and an angularly-adjustable frame, of a treadle-shai't, connected with the boX-frame by means of a centrally-pivoted rod, substantially as described, whereby the box-frame, grindingwheel, and shaft may be readily raised or lowered, regardless of the angle at which the grinding-wheel spindle is adjusted, as set forth.

BENJ. G. LUTHER.

Witnesses: j

CHARLES SELDEN, JOHN U. PURKIs. 

